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Finding the Fourth Proportional to 831, 1,243.68 and 783.60

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Solution

The fourth proportional to 831, 1,243.68 and 783.60 is: 1,172.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    831 : 1,243.68 = 783.60 : x
  2. Step 2: Convert to fraction form
    831/1,243.68 = 783.60/x
  3. Step 3: Cross multiply
    831x = 1,243.68 × 783.60
  4. Step 4: Simplify right side
    831x = 974,547.65
  5. Step 5: Solve for x
    x = 974,547.65/831
  6. Step 6: Final answer
    x = 1,172.74

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.